Wireless engine monitoring system for environmental emission control and aircraft networking

ABSTRACT

A wireless engine monitoring system for an aircraft engine includes a housing and wireless transceiver that receives engine data, including engine data relating to environmental engine emissions. A processor processes the engine data and generates an alarm report when the environmental engine emissions exceed a threshold.

PRIORITY APPLICATION(S)

This is a divisional application of U.S. patent application Ser. No.15/063,856 filed Mar. 8, 2016, the disclosure which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention relates to real-time monitoring of aircraft engines andrelated components, and more particularly, this invention relates to awireless engine monitoring system used in aircraft sensor networking,meeting emission standards, and determining a maintenance schedule foran aircraft engine.

BACKGROUND OF THE INVENTION

Harris Corporation developed a Wireless Engine Monitoring System (WEMS)module that monitors aircraft engines in real-time without resorting toa larger ground data link unit that interfaces with many aircraftsystems. The WEMS module is disclosed in commonly assigned U.S. Pat.Nos. 6,943,699; 7,456,756; 7,595,739; 7,755,512; and 9,026,336; thedisclosures which are hereby incorporated by reference in theirentirety. In one example, the WEMS module transmits its engine data to aCabin Wireless LAN Unit (CWLU) for further processing at the flight deckor for transmission via a satellite to a ground based engine serviceprovider.

The WEMS module is interfaced in one example to the Full AuthorityDigital Engine Controller (FADEC)/Engine Control Unit (ECU) and mountedon the engine, and can record, store, encrypt and transmit “full flight”engine data by recording hundreds of engine parameters, for example,with a one second or less sampling frequency. It has a preferredconformal antenna and RF transceiver to download (and upload) data usingRF/802.11/cellular techniques, including other spread spectrumtechniques as non-limiting examples.

This collection and storage of “full flight” engine data using the WEMSmodule allows advanced prognostics and diagnostics on the engine andincreases engine “time-on-wing” (TOW) and decreases engine maintenancecost per hour (MCPH). The WEMS data is downloaded in one example using aRF/(802.11) spread spectrum/cellular signal to an airport server forprocessing and/or transported over the internet, PSTN, cellular or othercommunications network to another workstation for post flight analysis.Data can also be uploaded to the WEMS module, including algorithms foron-board processing. The WEMS module provides an automated wirelesssolution installed directly on the engine, recording full flight enginedata for both large and small turbine engines in large megabyte filesand using a high speed data link to extract.

Recently, the Federal Aviation Administration (FAA) has been workingwith airlines to identify pollutants emitted from aircraft engines andstudy their impact on the environment and climate change. Aircraftengines emit carbon dioxide (CO₂), water vapor (H₂O), oxides of nitrogensuch as nitrogen oxide or dioxide, oxides of sulfur, carbon monoxide(CO), partially combusted or unburned hydrocarbons (HC), particulatematter (PM), and other compounds and pollutants. Many of these compoundsand pollutants are emitted by aircraft close to the surface of theearth, for example, less than 3,000 feet above ground level. Excessivecarbon monoxide and some hydrocarbons are produced when the aircraftengines are operating at their lowest combustion efficiency, forexample, while wheels are on the ground at initial take-off or landing.The greater quantities of aircraft engine emissions and pollutants areemitted at the airport or just after or before landing at the airport.For this reason, many civil aviation authorities require monitoring ofthese aircraft engine emissions. Some countries have even suggested thatfines be imposed on aircraft companies that emit pollutants that exceeda threshold when the aircraft is in their area.

Related to these issues of reducing aircraft emissions are thesafety-related applications of the numerous sensors contained within theaircraft and ensuring redundant operation in cases of emergency. Anaircraft has redundant wiring that adds weight to the aircraft, which inturn increases pollutants emitted from the aircraft engine. This alsocreates a point of failure since there are large numbers of redundantwires. For that reason, new standards have been developed for a WirelessAvionics Intra Communications (WAIC) system to allow wireless radiocommunication between two or more points on a single aircraft while alsocommunicating with integrated wireless and/or installed components inthe aircraft, such as wireless sensors. A WAIC is based on short rangeradio technology having distances usually less than 100 meters and lowtransmit power levels of 10 milliwatts for low rate data communicationsand 50 milliwatts for high rate data applications. WAIC systems providedissimilar redundancy, fewer wires and reduced connector pin failures.These systems also lower the risk of cracked insulation and brokenconductors, and permit mesh networking between gateway network nodesthat communicate with wireless sensors, including displays andactivators, and provide communication redundancy in emergencies whenwired connectors fail. The reduced wiring and resultant reduced aircraftweight also enables less fuel burn, helping to reduce emissions and meetmore stringent environmental standards and thresholds required by somejurisdictions. The WAIC systems may also increase reliability byreducing the amount of aged wiring, simplifying and reducing thelife-cycle cost of airplane wiring, and obtaining more data fromaircraft systems and surfaces with new wireless sensors.

SUMMARY OF THE INVENTION

A monitoring system for an aircraft engine comprises a plurality ofwireless engine sensors associated with the aircraft engine and eachconfigured to sense an engine parameter as engine data relating toenvironmental engine emissions from the aircraft engine and transmit theengine data. An engine monitoring module comprises a housing configuredto be mounted at the aircraft engine, a wireless transceiver carried bythe housing and configured to receive the engine data from the enginesensors, a memory carried by the housing, and a processor carried by thehousing and coupled to the memory and the wireless transceiver. Theprocessor is configured to collect and store in the memory the enginedata, and process the engine data and generate an alarm report when theenvironmental engine emissions exceed a threshold.

The engine data for the environmental engine emissions may comprise theexhaust concentration of at least one of total hydrocarbons (THC), totalorganic gases (TOC), particulate matter (PM), carbon monoxide (CO),sulfur dioxide, and oxides of nitrogen. The processor may be configuredto process the engine data based on phase of flight of the aircraft andgenerate an alarm report when the environmental engine emissions exceedthe threshold for a respective phase of flight. The phase of flight mayinclude at least one of the aircraft's taxiing, take-off, climb, cruise,descent, final approach and taxiing.

The wireless transceiver may be configured to transmit the alarm reportinto the aircraft. At least one communications device may be positionedwithin the flight deck that receives the alarm report and includes adisplay configured to display the alarm report to the crew in the flightdeck. The engine parameters may comprise data regarding the sensedexhaust gas temperature (EGT) of the aircraft engine during flight, andthe processor may be configured to generate the alarm report when theEGT exceeds a threshold. The plurality of engine sensors may comprise asensor configured to measure the particle emissions in the exhaust plumeof the aircraft.

A ground based receiver may receive the engine data relating to theenvironmental engine emissions. A processor may be coupled to the groundbased receiver and configured to correlate the engine data relating tothe environmental engine emissions to the phase of flight of theaircraft engine and perform an analysis to determine a maintenanceschedule for the aircraft engine. The processor may be configured toperform an analysis of the data relating to the environmental engineemissions based on the phase of flight of the aircraft engine using aBayesian network. The plurality of wireless engine sensors may beconfigured to sense a low compressor speed (N1), a high compressor speed(N2), engine oil pressure, engine oil temperature and fuel flow of theaircraft engine. The plurality of wireless engine sensors may also beconfigured to measure at least one of barometric pressure, air moisturecontent, wind speed, and air temperature.

A monitoring system for an aircraft engine comprises an enginemonitoring module comprising a housing configured to be mounted at theaircraft engine, a wireless transceiver carried by the housing, a memorycarried by the housing, and a processor carried by the housing andcoupled to the memory and the wireless transceiver. The processor isconfigured to collect and store in the memory engine data relating to aplurality of engine parameters sensed during operation of the aircraftengine by a plurality of engine sensors. A ground based receiver may beconfigured to receive the engine data from the wireless transceiver. Aprocessor may be coupled to the receiver and configured to receive theengine data, correlate the engine data to the phase of flight of theaircraft engine, and perform an analysis to determine a maintenanceschedule for the aircraft engine.

The processor may be configured to perform an analysis of the enginedata using a Bayesian network. The Bayesian network may comprise adecision tree having variables comprising ranges of engine performanceparameters. The engine performance parameters may comprise engine datarelating to environmental engine emissions from the aircraft engine. Theengine data for the environmental engine emissions may comprise theexhaust concentration of at least one of total hydrocarbons (THC), totalorganic gases (TOC), particulate matter (PM), carbon monoxide (CO),sulfur dioxide, and oxides of nitrogen. The phase of flight may includeat least one of the aircraft's taxiing, take-off, climb, cruise,descent, final approach and taxiing. The engine parameters may compriseengine data regarding the sensed exhaust gas temperature (EGT) of theaircraft engine during flight. The engine parameters may comprise enginedata for a low compressor speed (N1), a high compressor speed (N2),engine oil pressure, engine oil temperature and fuel flow of theaircraft engine. The engine parameters may also comprise engine data forbarometric pressure, air moisture content, wind speed, and airtemperature.

An aircraft comprises a wireless sensor server contained within theaircraft and a plurality of aircraft compartments. Each aircraftcompartment comprises a gateway network node comprising a wirelessgateway transceiver, and a plurality of wireless sensors each connectedto an aircraft component to be sensed. Each wireless sensor may comprisea sensor transceiver configured to receive aircraft data from the sensedaircraft component and transmit the aircraft data to the wireless sensorserver via the wireless gateway transceiver of the gateway network nodewithin the respective aircraft compartment.

At least one of the aircraft compartments comprises an engine nacelleand an aircraft engine supported within the engine nacelle. Theplurality of wireless sensors may comprise wireless engine sensors. Thegateway network node contained within the engine nacelle may comprise anengine monitoring module comprising a housing configured to be mountedat the aircraft engine, a wireless transceiver carried by the housingand configured to receive engine data from the wireless engine sensors,a memory carried by the housing, and a processor carried by the housingand coupled to the memory and the wireless transceiver and configured tocollect and store in the memory the engine data and transmit the enginedata to the aircraft sensor server.

Each wireless engine sensor may be configured to sense an engineparameter as engine data relating to environmental engine emissions fromthe aircraft engine. The engine data for the environmental engineemissions may comprise the exhaust concentration of at least one oftotal hydrocarbons (THC), total organic gases (TOC), particulate matter(PM), carbon monoxide (CO), sulfur dioxide, and oxides of nitrogen. Theaircraft may comprise an existing on-board communications network. Eachgateway network node may be connected to the existing on-boardcommunications network. The existing on-board communications network atthe engine nacelle may comprise a Full Authority Digital EngineController/Engine Control Unit (FADEC/ECU) connected to the enginemonitoring module. The existing on-board communications network maycomprise an avionics data bus. An aircraft component may comprise anactuator or display.

The plurality of aircraft compartments may comprise at least one of aflight deck, cabin compartment, avionics compartment, cargo compartment,bilge, engine nacelles, fuel tanks, vertical and horizontal stabilizers,landing gear bays and flap members. The wireless sensor server maycomprise a server processor and server memory. The server processor maybe configured to store within the server memory the aircraft datareceived from each of the gateway network nodes. Each gateway networknode may be configured in a multi-hop network configuration tocommunicate among each other and the wireless sensor server and wirelesssensors using a wireless communications protocol. The wirelesscommunications protocol may comprise at least one of Time DivisionMultiple Access (TDMA), Frequency Division Multiple Access (FDMA), CodeDivision Multiple Access (CDMA), Space Division Multiple Access (SDMA),and Orthogonal Frequency-Division Multiplexing (OFDM).

A monitoring system for an aircraft engine comprises an enginemonitoring module having a housing configured to be mounted at theaircraft engine, a wireless transceiver carried by the housing, a memorycarried by the housing, and a processor carried by the housing andcoupled to the memory and the wireless transceiver. The processor isconfigured to collect and store in the memory engine data relating to aplurality of engine parameters sensed during operation of the aircraftengine by a plurality of engine sensors and transmit the engine datainto the aircraft. An engine controller is coupled to the aircraftengine and configured to control engine operating parameters. The enginecontroller is configured to receive the engine data transmitted from theengine monitoring module and receive current weather forecasting dataand process the engine data and current weather forecasting data andchange engine operating parameters during flight based on predictedflight operations caused by weather changes.

The engine controller may be contained within the flight deck of theaircraft. The sensed engine parameters include environmental engineemissions comprising the exhaust concentration of at least one of totalhydrocarbons (THC), total organic gases (TOC), particulate matter (PM),carbon monoxide (CO), sulfur dioxide, and oxides of nitrogen. The enginecontroller may be configured to process the engine data based on phaseof the flight of the aircraft. The phase of flight may include at leastone of the aircraft's taxiing, take-off, climb, cruise, descent, finalapproach and taxiing. The sensed engine parameters may comprise dataregarding the sensed exhaust gas temperature (EGT) of the aircraftengine during flight. A sensor may be connected to the engine controllerand configured to measure the particle emissions in the exhaust plume ofthe aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome apparent from the detailed description of the invention whichfollows, when considered in light of the accompanying drawings.

FIG. 1 is a partial fragmentary, isometric view of a jet engine showingthe WEMS module mounted on the engine and interfaced with the FADEC/ECUin accordance with a non-limiting example.

FIG. 2 is a block diagram showing the WEMS module interfaced with theFADEC/ECU for downloading full flight engine data files and uploadingalgorithms and other data in accordance with a non-limiting example.

FIG. 3 is a block diagram showing WEMS engine data that may bedownloaded to an airport server and transferred by PSTN, Internet orcellular infrastructure to a real-time analysis workstation inaccordance with a non-limiting example.

FIG. 4 is a block diagram showing a plurality of WEMS modules thatcommunicate wirelessly with ground based systems in accordance with anon-limiting example.

FIG. 5 is a high-level block diagram of the WEMS module showing basicfunctional components in accordance with a non-limiting example.

FIG. 6 is a cross-section of an example jet engine that generates engineevents to be collected by wireless sensors, for example, and stored andtransmitted from the WEMS module in accordance with a non-limitingexample.

FIG. 7 is a chart showing various jet engine event reports at enginestart and during flight that could be monitored by the WEMS module inaccordance with a non-limiting example.

FIG. 8 is a block diagram of the WEMS module showing details of themodule components for communicating with wireless sensors and operatingas a gateway network node in accordance with a non-limiting example.

FIG. 9 is a partial fragmentary view of an aircraft and its engines andthe WEMS module transmitting engine data to a cabin wireless LAN unit inaccordance with a non-limiting example.

FIG. 10 is a block diagram showing the WEMS module that communicateswith an Engine Wireless Sensor Network (EWSN) and Engine ServiceProvider (ESP) operations center in accordance with a non-limitingexample of the present invention.

FIG. 11 is a graph showing different phases of flight relative toaircraft engine emissions in accordance with a non-limiting example.

FIG. 12 is a graph showing standards for oxides of nitrogen with thrustversus pressure ratios.

FIG. 13 is a chart showing aircraft engine emissions data and derivedemission factors that may be used to determine a threshold for aircraftengine emissions.

FIG. 14 is a high-level flowchart showing the process of generating analarm report when aircraft emissions exceed a threshold.

FIG. 15 is a high-level flowchart showing a process for an analysis todetermine a maintenance schedule using engine emissions data inaccordance with a non-limiting example.

FIG. 16 is a high-level flowchart showing a process for using weatherfor existing data and the WEMS engine data to change engine operatingparameters.

FIG. 17 is an environmental view of an aircraft showing an aircraftmonitoring system having gateway network nodes communicating withwireless sensors and the WEMS module as a gateway network node inaccordance with a non-limiting example.

FIG. 18 is a block diagram showing a plurality of aircraft compartments,each having a gateway network node and wireless sensors in accordancewith a non-limiting example.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout, and prime notation is used toindicate similar elements in alternative embodiments.

In accordance with a non-limiting example, the WEMS module may be usedin an aircraft monitoring system as a gateway network node thatcommunicates with other gateway network nodes in a multi-hop networkconfiguration and communicates with a wireless sensor server andwireless sensors using a wireless communications protocol.

The WEMS module may also be used with the aircraft engine alone andprocess and store engine parameters as engine data relating toenvironmental engine emissions from the aircraft engine and process thatengine data. It may generate an alarm report when the environmentalengine emissions exceed a threshold. For example, when the aircraftapproaches an airport, the WEMS module may signal the pilot through analarm report that the environmental engine emissions have exceeded athreshold for that airport or jurisdiction and engine adjustments may bemade to stay within the emission guidelines established by thatjurisdiction or airport. Also, the engine parameters, including theenvironmental engine emissions, may be stored and downloaded to a groundbased receiver such as located at an engine service provider. The enginedata may be correlated to the phase of flight and an analysis, such as aprobability analysis, performed to determine a maintenance schedule forthe aircraft engine, for example, using a Bayesian network.

It is also possible to process weather forecasting data with the enginedata from the WEMS module, for example, in an engine controller that iscoupled to the aircraft engine and configured to control engineoperating parameters. The engine controller may be positioned at theflight deck and processes the engine data and current weatherforecasting data and change engine operating parameters during flightbased on predicted flight operations caused by weather changes. Thiscould include sensing environmental engine emissions and processingengine data based on phase of the flight of the aircraft. It is possibleto measure the Exhaust Gas Temperature and correlate that with sensedcarbon emissions and determine carbon credit data. Also, it is possibleto monitor real time and full flight engine data obtain from the WEMSmodule and measure carbon emissions to determine carbon credits.

Referring now to FIG. 1, the WEMS module 20 is mounted directly on thejet engine 22, and in an example, electrically connected to theFADEC/ECU control unit 24, which is also mounted on the jet engine. Thejet engine 22 shows basic elements of the turbine 26 and othercomponents. The jet engine cowling, also referred to as the nacelle 28,is shown in dashed lines and is a separate compartment. The WEMS module20 is disposed within the cowling, and as explained in greater detailbelow, may operate as a gateway network node in an aircraft monitoringsystem as part of a Wireless Avionics Intra Communications (WAIC)system. The WEMS module 20 may include the basic functional RF andmemory components, such as disclosed in the ground data link unit andengine monitoring system of commonly assigned U.S. Pat. Nos. 6,047,165;6,148,179; and 6,353,734, the disclosures which are hereby incorporatedby reference in their entirety. The WEMS module can be mounted atdifferent locations on the engine depending on the type of preferredconformal antenna and the nature of the cowling 28, i.e., nacelle, usedin the jet engine.

The WEMS module 20 not only may operate as a gateway network node, butit may also generate an alarm report when environment engine emissionsexceed a threshold. The WEMS module 20 also may communicateback-and-forth with a wireless sensor array shown generally at 29 inFIG. 1. The WEMS module 20 as a gateway network node communicates notonly with other gateway network nodes positioned in other aircraftcompartments, but also with individual wireless sensors forming thewireless sensor array 29.

Referring now to FIG. 2, a basic block diagram of a FADEC/ECU 24 that isoperative as a bidirectional multiplexer for signals to and from the jetengine 22 is illustrated. The signals include analog and digital signalsand the FADEC/ECU 24 gives commands to the engine from the flight deck30 of the aircraft 32. It also transmits engine status and healthsignals. Many signals are processed by the FADEC/ECU 24, which thentransmits the signals over an ARINC 429 bus 34 in this non-limitingexample at typically 10 kilobits per second to and from the flight deck30.

The WEMS module 20 in one example includes a separate data address as anIP address (for each module), which is linked to the serial number ofthe engine. The WEMS module 20 is mounted on the engine and interfaceswith the FADEC/ECU 24 such as through another port on the FADEC/ECU ordirectly into the ARINC 429 bus 34. The radio frequency transceivercapability is built into the WEMS module 20 and is operative forrecording, compressing and encrypting full flight data files. The WEMSmodule 20 typically will use a conformal antenna 40 that is formed inone example as a small patch antenna the size of a postage stamp, forexample, mounted on the housing, i.e., the casing 41, that forms aprotective housing for the WEMS module 20. Although a conformal antennais preferred, a separate antenna could possibly be used depending on thecowling and engine type on which the WEMS module 20 is mounted. Aseparate antenna could be mounted on a separate location on the fuselageor other location for enhancing communication.

The WEMS module 20 can use an archival data store for recording, storingand encrypting and then later transmitting “full flight” engine data.The WEMS module 20 can record hundreds of engine parameters with apreferred one second sampling frequency in one example. This samplingfrequency may be modified as explained in greater detail below. The WEMSmodule 20 thus allows advanced prognostic and diagnostic techniques toincrease engine “time on wing” (TOW) and decrease engine maintenancecosts. For example, the WEMS module 20 could be operative with jetengine diagnostic cells, such as used with prognostic and healthmanagement applications, including those designed by ImpactTechnologies, LLC of Rochester, N.Y.

The WEMS module 20 can download engine data by almost any type of radiofrequency signal, including spread spectrum modulation techniques. TheWEMS module 20 could be operative with cellular, internet, or PSTNcommunication infrastructures to download full flight engine data filesand upload algorithms or other data or programs. Each WEMS module willtypically include a separate Internet Protocol (IP) address such that itcan be separately addressable for identification and upload and downloadof data. The WEMS module 20 may also communicate wirelessly with thewireless sensor array 29 and also operate as a gateway network node andreceive engine data regarding environmental emissions. The engine datamay also be downloaded to an engine service provider for furtherprocessing such as to determine maintenance schedules.

FIG. 3 shows a high-level block diagram of an aircraft 32 that includesa WEMS module 20 that downloads engine data and uploads data foron-board processing to and/or from an airport server 42, which could beoperative with a communications network 44, such as a public switchedtelephone network (PSTN), the internet or a cellular infrastructure. Theairport server 42 includes a receiver and transmitter and communicatesthrough the communications network 44 to a post flight analysisworkstation, for example, as provided by an engine service provider(ESP) 48 or other station having the processing capability to analyzethe downloaded engine data, including emissions data, and determine thebest maintenance program for the aircraft engine, and thus, extend thetime the engine remains on the aircraft without removing the engine. Thereal-time analysis workstation at the ESP 48, for example, could bedirectly connected to the airport server or could receive engine datadirectly from the WEMS module 20.

During flight or as an aircraft approaches an airport, the WEMS modulemay process the engine data, including the environmental engineemissions as sensed by any wireless or wired sensors, and generate analarm report when the engine emissions exceed a threshold. The alarmreport would give notice to a pilot that the aircraft may be exceedingthe emission limits in a specific jurisdiction and be able to modifytheir engine operation such as throttle back. Also, the real-timeanalysis workstation at the ESP 48 may take the engine data, includingthe engine emissions, and correlate the engine data to the phase offlight of the aircraft engine and perform an analysis to determine amaintenance schedule for the aircraft engine. The time-on-wing may alsobe taken into consideration. Maintenance may be required if theemissions cannot be lowered or if the emissions indicate that service ormaintenance is required. The analysis may include using a Bayesiannetwork as explained below, including a decision tree having variablescomprising ranges of engine operating performance parameters related, inone example, to the engine emissions.

Referring now to FIG. 4, there is shown a representative example of anoverall communications system architecture for a wireless spreadspectrum data communications system that can be used with the WEMSmodule 20. The architecture in this example has three interlinkedsubsystems: (1) an engine WEMS subsystem 100; (2) a ground subsystem 200(typically airport based but not necessarily at the airport); and (3) aremote engine data control center 300 used for analyzing any downloadedengine data. The WEMS system 100 for one aircraft 32 could include aplurality of WEMS modules 20, each installed on an engine with fourengines 100 a-d illustrated. Two aircraft 32 and 32′ are illustratedeach with respective WEMS modules 20, 20′. Each WEMS module 20, 20′includes an airborne unit (AU) 102, 102′, each which includes theprocessor, transceiver, memory and other necessary components. Each WEMSmodule 20, 20′ is operative to communicate with a wireless router (WR)segment 201 of the ground subsystem 200 through a wirelesscommunications link 120. The following description proceeds withreference to one aircraft 32 and WEMS module 20 for purposes ofdescription.

The wireless router segment 201 routes the engine data files it receivesfrom the WEMS module 20, either directly to an airport base station 202via a wired Ethernet LAN 207, or indirectly through local area networks207 and airport-resident wireless bridge segments 203 in this onenon-limiting example. The wireless communication link 120 can be aspread spectrum radio frequency (RF) link having a carrier frequencylying in an unlicensed portion of the electromagnetic spectrum, such aswithin the 2.4-2.5 GHz S-band as one non-limiting example. The wirelesscommunication link 120 could also be an RF, internet, cellular, or otherlink.

The ground subsystem 200 in this example includes a plurality of groundand/or airport-resident wireless router segments 201, one or more ofwhich are distributed within the environments of the various airportsserved by the system. A respective ground and/or airport wireless router201 is operative to receive engine data that is wirelessly down-linkedfrom a WEMS module 20. Each ground subsystem wireless router 201 canforward engine data to a server/archive computer terminal 204 of a basestation 202, which can reside on a local area network 207 of the groundsubsystem 200 at an airport or other location.

The base station 202 can be coupled via a local communications path 207,to which a remote gateway (RG) segment 206 is interfaced over acommunications path 230, to a central gateway (CG) segment 306 of aremote engine data control center 300, where engine data files fromvarious aircraft are analyzed. As a non-limiting example, thecommunications path 230 can include an ISDN telephone company (Telco)land line, and the gateway segments can include standard LAN interfaces.Other communications networks, such as cellular, internet, or otherwireless communications can be used. It should be observed that othercommunications media, such as a satellite links or cellular, forexample, may be employed for ground subsystem-to-control centercommunications without departing from the scope of the invention.

The remote engine data control center 300 could include a systemcontroller (SC) segment 301 and a plurality of workstations (WS) 303,which are interlinked to the systems controller 301 via a local areanetwork 305. Engine safety, maintenance, and monitoring analysts are atthe remote engine data control center 300 to evaluate the engine datafiles conveyed to the remote engine data control center 300 from theairport base station segments 202 of the ground subsystem 200. Therespective workstations 303 may be allocated for different purposes.

The system controller 301 can have a server/archive terminal unit 304that preferably includes database management software for providing forefficient transfer and analysis of engine data files, as it retrievesdownloaded files from the ground subsystem. As a non-limiting example,such database management software may delete existing files from a basestation segment's memory once the files have been retrieved.

As described briefly above, and as diagrammatically illustrated in FIG.5, each WEMS module 20 generally can include a housing 21 andbidirectional wireless (radio frequency carrier-based) subsystemcontaining a processing unit such as a microprocessor 132 and associatedmemory or data store 134, serving as both an archival data store 134 aand a buffer 134 b for communications, including packet communications.The memory 134 is coupled to the FADEC/ECU. Processing unit 132 canreceive and compress the engine data and store the compressed data inits associated memory 134. A report can be generated by the processingunit 132, which includes many items of engine data and if a threshold ispassed for emissions from the engine.

The engine data and reports can be downloaded via the RF transceiver 136and its preferred conformal antenna 40. To provide bidirectional RFcommunication capability, the transceiver 136 is operative with thewireless router 201 shown in FIG. 4 for upload and download of data.Also, the WEMS module 20 may operate as a gateway network node andcommunicate wirelessly with the wireless sensor array 29 (FIG. 1) asfurther explained below.

If the RF communication link is spread spectrum, and a preferred 802.11link, each of a plurality of sub-band channels of an unlicensed 2.4-2.5GHz S-band segment of interest in this non-limiting example can beavailable and preferably used. Other unlicensed or licensed bands couldbe used. A wireless router 201 could continuously broadcast aninterrogation beacon that contains information representative of theemitted power level restrictions at an airport. Using an adaptive powerunit within its transceiver, the WEMS module 20 could respond to thisbeacon signal by adjusting its emitted power to a level that will notexceed communication limitations imposed by the jurisdiction governingthe airport. The wireless (RF) transceiver 136 then accesses the enginedata file stored in memory 134, encrypts the engine data and transmitsthe engine data file via a selected sub-channel of the wireless groundcommunications link to a wireless router 201.

The recipient wireless router 201 forwards the data file to the basestation segment temporarily until the file can be automaticallytransmitted over the communications path 230 to the remote engine datacontrol center 300 for analysis.

For purposes of reference, a jet engine is described with reference toFIGS. 6 and 7 on which the wireless engine monitoring system (WEMS)module 20 as described can be used. Each engine can have one enginemounted WEMS module 20 and each WEMS module can have a specific dataaddress, such as an internet address or other IP address, to allowservice providers to access the WEMS module and its data in nearreal-time and perform “intelligent” maintenance. This address is linkedto the engine serial number and will be used to store routine andcritical engine information. Use of the WEMS module can thus reduceengine maintenance cost per hour (MCPH).

FIG. 6 illustrates one cross-section of a jet engine indicated generallyat 400, showing basic components and engine air flow FADEC/ECU control402 to and from the jet engine that can be used for real-time monitoringof engine events. These events could be downloaded during the firstminute or so of initial take-off to a remote engine data control center300 or saved to memory in the WEMS module and later downloaded todetermine if “on wing” engine maintenance is warranted at thedestination.

For purposes of clarity, reference numerals to describe this jet enginebegin in the 400 series. As shown in FIG. 6, the engine air flowFADEC/ECU control 402 could include the core compartment bleeding; sumppressurization; sump venting; active clearance control; low pressure andhigh pressure recoup; and venting and draining functions. Thesefunctions could be monitored through basic FADEC/ECU control system 402,as known to those skilled in the art. The engine example in FIG. 6corresponds to a General Electric CF6-80C2 advanced design with aFADEC/ECU or PMC control having an N1 thrust management and common turbomachinery. Although this jet engine is illustrated, naturally othercontrol systems for different jet engines could be used, as known tothose skilled in the art.

The engine as illustrated has six variable stages and a ruggedized stageone blade with a low emission combustor and 30 pressurized nozzles andimproved emissions. It has a Kevlar containment to give a lowercontainment weight and a composite fan outer guide vane. It has anenhanced High Pressure Turbine (HPT) with a stage of one blade materialand advanced cooling and active clearance control.

The fan module includes an aluminum/Kevlar containment 404 and a 93-inchimproved aero/blade 406. It has compositive outer guide vanes 408 withan aluminum/composite aft fan case 410 and a titanium fan frame 412 forreduced losses. It additionally has a four stage orthogonal booster 414and a variable bypass valve (VBV) between the fan struts (with 12locations) 416. The engine includes a compressor inlet temperature (CIT)probe 418.

The high pressure compressor includes an IGV shroud seal 420 and a bladedovetail sealing 422 with a trenched casing of stages 3-14 424. Thecompressor includes a vane platform sealing 426 and a short cord stage 8low loss bleed system 428 and improved rubcoat reduced clearances 430.

The compressor rear frame includes a combustor 430 and igniter plug 432with a fuel nozzle 434 and outer guide vane 436. It includes a vent seal438 and 4R/A/O seal 440 and 4R bearing 442 and 4B bearing 444. It alsoincludes a 5R bearing 446 and 5R/A/O seal 448, a diffuser 450 andpressure balance seal 452. The compressor rear frame also includes astage 1 nozzle 454.

The high pressure turbine area includes an active clearance for controlstages 1 and 2, and coated shrouds indicated at 456. It also includesdirectionally solidified stage 1 blades and damped blades 458 and acooling air delivery system. The high pressure turbine includes athermally matched support structure, and an active clearance control andsimplified impingement with a cradled vane support and linear ceiling.The improved inner structure load path has improved roundness control,solid shrouds and improved ceiling. These components are located in thearea generally at 460 of the high pressure turbine area.

Low pressure turbine technology area includes a clearance control 462, a360° case 464, aerodynamic struts 466 that remove swirl from the exitgas and a turbine rear frame 468 formed as a one piece casting.

Many of these components include wireless engine sensors and structuralforce sensors that generate signals during initial take-off andthroughout flight. Signals can be relayed via the WEMS module 20 to anon-ground maintenance crew and/or separate remote engine data controlcenter having its own processor and data analytics for advancedanalysis.

FIG. 7 illustrates components that were monitored during engine start inone example, including the engine hydraulic system, the oil pressure(psi), the engine cut-off switch, oil temperature (deg C.), fuel flow(lb/hr), the N2L and N1L both in percentage terms, oil temperature andEGT, both in centigrade, and W_(f). Some of the ranges are shown on thevertical axis of the graph, while time is shown on the horizontal axisof the graph.

In accordance with a non-limiting example and as described in furtherdetail below, the environmental engine emissions may be sensed andprocessed within the WEMS module 20, which generates an alarm reportwhen the environmental engine emissions for individual or combinedcomponents such as total hydrocarbons exceed a threshold. In onenon-limiting example, the threshold could be established by theInternational Civil Aviation Organization (ICAO) for specific countriesor general international standards of emissions from aircraft enginesduring different phases of flight. The engine data for the environmentalengine emissions could be sensed by other sensors so that in anon-limiting example the exhaust concentration of at least one of thetotal hydrocarbons (THC), total organic gases (TOG), particulate matter(PM), carbon monoxide (CO), sulfur dioxide, and oxides of nitrogen maybe established. Individual component hydrocarbons and other organicgases may be sensed.

An infrared laser and associated sensor or other plume analysis device480 (FIG. 6) may be used to detect plume emissions or other techniquesmay be used for analyzing the plume originating from the aircraftexhaust and determine more accurately in conjunction with the wirelessor wired engine sensors the environmental engine emissions from theaircraft. Specific sensors may be used to measure emissions, includingsensors for measuring nitrogen dioxide (NO₂), nitric acid (HNO₃), andammonium nitrate (NH₄NO₃) particles and other particulate matter andinorganic or organic compounds at the immediate jet engine exhaust orwithin the plume. This will allow early identification of engines thatexceed the ICAO limits.

There is now described relative to FIGS. 8-10 the WEMS module that mayalso communicate as a gateway network node in multiple-hop communicationwith other gateway network nodes located in other engine compartmentsand communicate with an engine wireless sensor network (EWEN), forsampling wireless engine sensors at different sampling rates, and forgenerating an alarm report if emissions from the engine exceed athreshold, for example, as established by the ICAO and for determining amaintenance schedule for the engine. For purposes of description,reference numerals begin in the 500 series. The reference numerals forthe WEMS module 20, jet engine 22, FADEC/ECU control unit 24, jet enginecowling or nacelle 28, flight deck 30 at the cabin, aircraft 32, ARINC429 bus 34, conformal antenna 40, and casing 41 (housing) remain thesame throughout the description with similar reference numerals.

FIG. 8 is a block diagram of the WEMS module 20 similar to that shown inFIG. 5, but showing greater details of different functional componentsand subcomponents that can be used in accordance with a non-limitingexample. The FADEC 24 interfaces with the WEMS module 20 and providespower to a power controller 502 in the WEMS module that interoperateswith a baseband Media Access Control (MAC) circuit 504 and dualWiFi/WiMAX radio 506, which in turn operates as a transceiver inaccordance with 802.11 and 802.16 standards. In one example, it is afirst wireless transmitter. This transceiver (radio) 506 could operatewith other standards, however, to transmit and receive data through theconformal antennas, which in this example, correspond to a transmit (Tx)conformal antenna 42 a and receive (Rx) conformal antenna 42 b.

The FADEC 24 communicates over the ARINC 429 bus 34 with a processor510, which in this non-limiting example corresponds to a system on achip (SOC) such as a Holt HI-8582/8583 integrated circuit chip. Thischip interoperates with an interface Field Programmable Gate Array(FPGA) 512, which interoperates with an ATA controller 514 and enginedata storage 516, for example, a 60 GB flash memory. The interface FPGA512 interoperates with a processor as a WEMS host CPU 518, which inturn, interoperates with the program flash and RAM 520 and the basebandmedia access control circuit 504. An associated Engine Wireless SensorNetwork (EWSN) Central Processing Unit (CPU) 522 and transceiver 523 canact as an interrogation unit and receiver for wireless engine sensors asexplained below. The transceiver (radio) 523 can transmit and receivedata through conformal antennas, such as the example illustrated attransmit (Tx) conformal antenna 524 a and receive (Rx) conformal antenna524 b.

As illustrated, the receive conformal antenna 524 b may receive enginedata and environmental emissions data from wireless sensors and othersensors or devices such as infrared sensor and optics and receiver thatsense the emissions at the engine itself and in the plume. The same datacould be transmitted to the FADEC. The radio 506 could operate withdifferent protocols in order to transmit and receive data with othergateway network nodes as explained in greater detail below.

In this system, no aircraft modification is required and no manualintervention is required after the WEMS module 20 is installed on theaircraft engine. As indicated below during flight, the WEMS module 20acquires, stores and encrypts “full flight engine data” and canautomatically and wirelessly download engine data during flight orpost-flight. In accordance with a non-limiting example of the presentinvention, the WEMS module 20 can acquire significant quantities of dataduring flight and provide global “real-time” downloading of thatacquired engine data such as using a communications protocol inconformance with ARINC 429. This is a technical standard for theavionics data bus used on most higher-end commercial and transportaircraft as a two-wired data bus and data protocol to support anavionics local area network (LAN). It is a self-clocking andself-synchronizing serial data bus with a transmit and receive onseparate ports. The twisted pair wires provide for balanced differentialcommunications signaling.

Each ARINC communications packet typically has a 32-bit value and fivefields, including a parity bit, a sign/status matrix (SSM) to indicatewhether a data field is valid, a normal operation (NO) to indicate thatdata in the word is considered to be correct data; a functional test(FT) to indicate that data is provided by a test source; a failurewarning (FW) to indicate a failure that causes the data to be suspect ormissing; and a no computed data (NCD) to indicate that data is missingor inaccurate. The SSM as a sign/status matrix can indicate the sign ofthe data or other orientation such as north/south or east/west. TheARINC 429 system on a chip circuit 510 such as the Holt integratedcircuits HI-8582 or HI-8583 is a silicon gate CMOS device thatinterfaces a 16-bit parallel data bus directly to the ARINC 429 serialbus 24. The ARINC 429 processor 510 includes two receivers each withlabel recognition, 32×32 FIFO and an analog line receiver. Up to 16labels can be programmed for each receiver.

FIG. 9 illustrates a fragmentary sectional view of an aircraft 32 andtwo aircraft engines 22, each having an engine mounted WEMS module 20 inaccordance with a non-limiting example of the present invention. Theaircraft 32 includes the flight deck 530 having a cabin wireless LANunit (CWLU) 532 that operates as a wireless access point and receivescommunication signals from the WEMS module 20. The CWLU 532interoperates with a satellite communications unit 540 that includes asatellite data unit 542, a low noise amplifier/power amplifier (LNA/PA)544 and high gain satellite communications antenna 546. These componentsform a second wireless transmitter for a satellite communications link.The CWLU 532 also interoperates with a UHF transceiver 550 that can beused for air-to-ground communications such as the older Air-to-GroundRadiotelephone bands used on aircraft. The UHF transceiver also operatesas a second wireless transmitter. Multiple hop communications isillustrated using the WEMS module 20, CWLU 532, and a satellite 554,which communicates with a ground entry point 556 user satellite dishsuch as a satellite receiving dish that receives data for an engineservice provider (ESP) 562. During flight, the WEMS module 20 wirelesslyconnects to the cabin wireless LAN unit 532 and can download critical“in flight engine safety data” to the ESP 562 or have an on-boardprocessor analyze the data. This data can support FAA ETOPS (ExtendedTwin Operations) for oceanic routes.

The satellite communication link provides “real-time” engine datatransfers and supports critical engine decisions at the ESP or on-board,including “in flight engine shut downs” to determine if one of theengines should be shut down. Real-time analysis of aircraft engine datacan be accomplished at the engine service provider 562, includingperformance-based contract reports for engine diagnostics, health andstatus of an aircraft engine, performance burns, time on wing and theenvironmental impact (carbon emissions) or on-board the aircraft.Satellite communications can include different communications signalingand protocols, including Direct Broadcast Satellite (DBS), the FixedSatellite Service (FSS), Ku, Ka and C band communications.

Alternatively, the UHF transceiver 550 can be used for communications at848-850 MHz and 894-896 MHz as part of the older telephone band that canconnect to the terrestrial ground system. The system as shown in FIGS. 8and 9 allows significant “high value” and “time critical” data to bedownloaded during flight and provides global “real-time” downloading ofengine data. The WEMS module 20 interfaces with resources commonlyavailable on international flights, including the WiFi cabin wirelessLAN unit 532 in accordance with non-limiting examples operating underthe ARINC 763 standard, which applies to servers on board commercialaircraft, allowing a passenger to have an “office in the sky.” Accesscan be provided to the airborne satellite communications that operate inaccordance with the ARINC 741 standard using the satellite data unit 542and other components as described. Airlines can now more closely monitoraircraft engine performance including meeting IAW ETOPS certificationrequirements that apply to twin engine aircraft on routes with diversiontimes more than 60 minutes using one engine and applies on routes withdiversion times more than 180 minutes for airplanes with more than twoengines. ETOPS is the acronym for Extended Twin Operations as defined bythe U.S. Federal Aviation Administration (FAA) and allows thetwin-engine airliners such as an AirBus A300 or Boeing 737 and up toBoeing 787 to fly the long distance routes that were previouslyoff-limits to twin-engine aircraft.

The WEMS data as real-time aircraft engine data allows a flight crew tomake a decision to do an in-flight check-up and if necessary shut downor adjust the engine thrust of an engine. Algorithms can be programmedinto the WEMS module 20 or a processor at the flight deck or at a groundbased ESP 562 to provide the processing to determine engine operatingparameters based on the sensed engine data and determine if an in-flightshutdown should occur if certain engine operating parameters have beenexceeded. Algorithms can be uploaded to the WEMS module 20 even duringflight, allowing the WEMS module 20 to be configurable “on-the-fly.” Itis also possible to populate a request from the flight deck to the WEMSmodule 20 as to what exceedances are to be investigated and processeddepending on environmental or other conditions. For example, it ispossible to configure the WEMS module 20 to download only specificmonitored parameters and data during flight instead of downloading alarge amount of data. The WEMS module is thus configurable as to datacollection, storage and transmission, including the exhaust emission.The WEMS module 20 is configurable and can be programmed from the flightdeck or from an ESP 562. For example, if vibration occurs during flight,it is possible to increase the sampling frequency for various vibrationengine sensors, while reducing the sampling frequency of other sensorssuch that more data is collected during flight concerning vibrationstatistics.

The WEMS module in one example operates in accordance with the IEEE802.11 or IEEE 802.16 standards and is implemented with a Wireless LocalArea Network (WLAN) 530 at a preferred 2.4 GHz frequency band. It alsooperates in the 3.6 and 5.0 GHz frequency bands. Over-the-air modulationtechniques use the same basic protocol such as defined in the 802.11band 8011g protocols, typically using the 2.4 GHz ISM band, which divideseach of the various bands into channels. For example, the 2.4000 through2.4835 GHz band is divided into 13 channels that are spaced 5 MHz apart,with availability of the channels often regulated by each country. Thus,depending on worldwide geographical location of the aircraft, the WEMSunit 20 can communicate via its radio 506 on different channels and atdifferent powers depending on jurisdictional requirements at thespecific locale. Some of the channels can also overlap depending onlocal requirements. The data frames are typically divided into specific,standardized sections, which include a MAC header, payload, and framecheck sequence (FCS). Different MAC headers and frame control fields canbe used and subdivided into various subfields. These may be modifieddepending on the geographical location of the aircraft and localjurisdictional rule.

The 802.16 is a wireless broadband standard for a wireless metropolitanarea network as a wireless MAN, commercialized under the name “WiMAX”(Worldwide Interoperability for Microwave Access). WiMAX standardizesthe air interface and related functions with the wireless local loop. Itrequires a physical device layer (PHY) and operates with scalable OFDMA(Orthogonal Frequency Division Multiple Access) to carry data andsupport channel bandwidth between about 1.25 MHz and 20 MHz with about2,048 subcarriers. It supports adaptive modulation decoding and anefficient 64 QAM coding scheme. In some instances, 16 QAM and QPSK canbe used. The WEMS module 20 and other associated components of thesystem may include Multiple-in, Multiple-out (MIMO) antennas to providenon-line-of-sight propagation (NOLS) characteristics for a higherbandwidth and a hybrid automatic repeat request (HARQ) for good errorperformance. The MAC sublayer can include a number of convergentsublayers that describe how the wire line technology such as Ethernet,Asynchronous Transfer Mode (ATM) and internet protocol (IP) areencapsulated on the air interface and how data is classified. Theadvanced Encryption Standard (AES) or Data Encryption Standard (DES) canbe used during data transfer for higher security. Various power savingmechanisms can be used, including a sleep or idle mode. The quality ofservice (QOS) can be supported by allocating each connection between asubscriber station and base station.

FIG. 10 illustrates how the WEMS module 20 can interoperate in awireless connection with an existing Engine Wireless Sensor Network(EWSN) 600 that is formed by a plurality of different wireless enginesensors illustrated in this example as individual nodes 600 a-f, toprovide precise monitoring of the rotating subsystem such as the turbineblades and bearing assemblies in the aircraft engine, and gas pathparameters such as temperature, vibration, strain and pressure. Althoughonly six wireless engine sensors are illustrated, it should beunderstood that the engine wireless sensor network 600 for one jetaircraft engine can include at a minimum hundreds of such wirelessengine sensors. The sensors will sense the different engine parametersthat include engine emissions. A separate EWSN CPU 522 (corresponding tothe EWSN CPU in FIG. 8) at the WEMS module 20 can interoperate with theengine data received from different wireless engine sensors forcommunications and that CPU can configure the wireless sensors formingthe EWSN 600 to change sampling rates and interrogate sensors through anappropriate wireless transceiver that interoperates with each of thewireless engine sensors. The engine data received from the wirelessengine sensors can be processed as explained above and aircraftcomponents adjusted through the FADEC or through wireless communicationswith selected sensors.

The WEMS module 20 not only interfaces to the FADEC 24 as illustrated inFIG. 10, but also interface wirelessly to the wireless engine sensorsthat are configured to form the EWSN 600 and monitor the critical engineparameters. The EWSN topology can vary from a simple star network to anadvanced, multiple hop wireless mesh network. Propagation between thehops and the network can be by routing or flooding. As shown in FIG. 10,various wireless engine sensors include a fuel flow sensor (S_(F));temperature sensor (S_(T)); pressure sensor (S_(P)); level sensor(S_(L)); acceleration sensor (S_(A)); and vibration sensor (S_(V)). Thisis only a representative sample, of course, for illustration purposes,and many other wireless engine sensors are employed in the aircraftengine. Each of the wireless engine sensors can include varioustransducers that are bidirectional and provide engine control. Eachwireless engine sensor forms a wireless node and may include a sensingmechanism and includes a radio transceiver and antenna and amicrocontroller (processor) and associated software and an energy (orpower) source. This allows real-time detection and diagnosis for faultsthat can be alerted to a pilot.

The EWSN 600 interoperates with the WEMS module 20 and provides a costeffective method to monitor, detect and diagnose problems and targetsmechanically stressed components within a turbine unit or othercomponent of the engine. Use of the EWSN 600 also provides anopportunity for data fusion between the FADEC 24 and EWSN data sourcesto automatically and wirelessly forward data to the ground based EngineService Provider operations center 562 for post flight analysis andallow detection, diagnosis and prognosis of problems occurring withindifferent turbine components. The data obtained from the EWSN 600provides for early detection and diagnosis of turbine component faultsand helps prevents catastrophic failures and allows real-time dataacquisition for valuable engine operational, performance and designinformation. The flight deck 30 can include the cabin wireless LAN unit532 that includes a local engine diagnostics unit 574 that may be aprocessor or other CPU for local engine diagnostics.

The local engine diagnostics 574 may include an engine controller 578that is coupled to the aircraft engine and configured to control engineoperating parameters. This could be a wired connection to the engine ora wireless connection. The engine controller receives engine data andalso weather forecasting data and processes the engine data and currentweather forecasting data and changes engine operating parameters duringflight based on predicted flight operations caused by weather changes aswill be explained in greater detail below. The WEMS data may include thesensed engine parameters as the environmental engine emissionscomprising the exhaust concentration of at least one of totalhydrocarbons (THC), total organic gases (TOC), particulate matter (PM),carbon monoxide (CO), sulfur dioxide, and oxides of nitrogen. The sensedengine parameters may also include the exhaust gas temperature (EGT) ofthe aircraft engine during flight. Sensed engine parameters also mayinclude the particle emissions sensed in the exhaust plume of theaircraft.

FIG. 10 also illustrates how the engine wireless sensor network 600 maydownload engine emissions data. The engine data having the relatedengine emissions data may be transmitted from the WEMS module 20 toother gateway network nodes for storage in the sensor server. The datais also stored in the WEMS module 20. The engine data together havingthe engine emissions data may be downloaded to an engine serviceprovider (ESP) such as illustrated at 562 in FIGS. 9 and 10 andanalyzed. A processor may receive the engine data, correlate the enginedata to the phase of flight of the aircraft engine and perform ananalysis to determine a maintenance schedule for the aircraft engine. Ananalysis of the engine data may include using a Bayesian network thatincludes a decision tree having variables comprising ranges of engineperformance parameters as related to engine emissions, for example.Additionally, the WEMS module may analyze with its processor the engineemissions data and generate an alarm report when the engine emissionsexceed a threshold. This is particularly relevant when an aircraft isapproaching an airport that may have jurisdictional laws that requireemissions to not exceed a threshold and, if possible, the pilot mayadjust engine operation to come within the emissions limits. Also, itwould give the pilot necessary information for any engine maintenancethat may be required. For example, the fuel flow delivery system mayhave to be cleaned and other short-term maintenance operations performedon the jet engine. If the WEMS module 20 generates an alarm report, itmay be displayed on a mobile display device 575, such as a tablet devicefor the flight crew with the ability to process and display other dataon the device.

FIG. 11 shows a graph of the different phases of flight and the type ofenvironmental engine emissions data that can be measured as anon-limiting example, including engine operating parameters related tothe RPM of the turbine (N1), the air/fuel ratio (A/F) and the fuel flowin kg/s. Other environmental engine emission parameters that may bemeasured to obtain the engine emission data include carbon dioxide (CO₂)as a percentage, the carbon monoxide (CO), hydrocarbons (HC), oxides ofnitrogen NO_(X)), all in parts per million (PPM). This data may includethe carbon monoxide (CO) or hydrocarbons (HC) as CH₄ and the oxides ofnitrogen as NO₂ as grams per kilogram (kg) of fuel. The graph of FIG. 11shows how environmental emissions for certain components increase duringidle and at the lower engine speeds and are minimal at cruise. Differenttypes of wireless and/or wired engine sensors may be used to sense andmeasure environmental emissions. Other devices for sensing engineemissions include an aerosol mass spectrometer (AMS), a multi-angleabsorption photometer (MAAP), a condensation particle counter (CPC), anddifferential mobility analyzer (DMA) as non-limiting examples. Otherexamples may be used.

It is also possible to process data regarding the engine gas temperature(EGT) versus the fan speed, for example, the core speed (N2) and fanspeed (N1). If a difference in temperature on EGT from the average of athreshold of about 5 to 10 degrees is sensed, this may indicatedeterioration of the engine. It has been found that a fan speed versusfuel flow may be analyzed and a 2% change from threshold is significant.These are example thresholds that can be used for determining when analarm report should be generated.

Often gauges are not reliable and it is possible to look at the enginecore speed EGT and fuel flow. Performance deterioration of the jetengine would tend to increase combustor inlet temperature and thefuel-air ratio, which increases smoke emissions. Measurements of theindividual hydrocarbon species indicates that the emission indices formost of the major species of hydrocarbons decrease with increasingengine power in proportion to each other. This has also been seen withformaldehyde, which is a plentiful emitted hydrocarbon and can bemeasured accurately. The particle compounds as particulate matter (PM)may include sulfate and organic volatile fractions. Some of thesecompounds may also be measured in the plume by infrared laser andrelated optics and receivers and received information processed in adetector. It is believed that sulfate contribution has little dependenceon engine power, but the organic components in the exhaust are greatestat low engine powers.

Three contributors to carbonyl emissions are formaldehyde, acetaldehyde,and acetone. The WEMS module 20 will analyze these environmentalemissions and generate an alarm report as the plane approaches anairport and emits excessive emissions or at landing. It can alsogenerate an alarm report after take-off or during cruising if emissionssuddenly increase. The WEMS module 20 may also forward the emissionsdata and other engine reporting data to the flight deck via the cabinwireless LAN unit (532) or the gateway network nodes, as explained ingreater detail below, so that the pilot or other crew member at theflight deck can retrieve the data and display it on a display devicelocated at the flight deck, for example, a tablet, phone, or otherdevice 575 (FIG. 10).

This type of information is beneficial to the flight crew since nitrogenoxides are produced at higher engine power settings. The nitrogen oxideemission index also has a high value at a minimum idle thrust, such aswhen the aircraft is parked at the airport. The hydrocarbons decreasedwith increasing power and at a minimum thrust, such as about 21%, forexample, the power settings referred to as minimum idle. Thehydrocarbons were at maximum concentrations and the emission index ofthe hydrocarbons was the highest at the minimum idle thrust. The carbonmonoxide emissions increased with the decreasing power settings and thecarbon monoxide emission indices were the highest value at minimum idlethrust.

It should be understood that aircraft pollutants may transformphysically and/or chemically in three different zones: (1) after exitingthe combustor within the engine, (2) downstream from the engine in thehot exhaust plume, and (3) after emissions have cooled and mixed withthe ambient atmosphere. The heavier hydrocarbons may condense at theaircraft engine exit when the hot combustion gases mix with ambient airto quickly cool the gas stream and form aerosol particles. At theexhaust plume, some emissions continue to cool and some moleculesundergo chemical reactions producing other molecules that condense intoparticles that collide in the plume and form larger particles, althoughstill microscopic in size. Some of the resulting particulate matter (PM)in the plume can be solid or liquid and include carbon in soot,inorganic salts such as ammonium nitrate and ammonium sulfate, and heavyhydrocarbons that condense into aerosol particles.

Some of the emissions have different effects both on climate changeand/or air quality. For example, the CO₂, H₂O, nitrogen oxides, sulfuroxides and particulate matter, such as non-volatile compounds, all mayhave an impact on climate change while the same products, includinghydrocarbons, methane (CH₄), and carbon monoxide (CO) may impact airquality. The carbon dioxide is a product of complete combustion ofhydrocarbon fuel, for example, the jet fuel and combines with oxygen inthe air to produce CO₂. The water vapor is also a product of completecombustion. Hydrogen in the fuel combines with oxygen in the air toproduce the water in the condensation trails as the contrails. Theoxides of nitrogen are produced when air passes through the hightemperatures/high pressure combustion chambers in the aircraft engineand the nitrogen and oxygen that are present in the air form thenitrogen oxides. These nitrogen oxides contribute to the ozone andsecondary particular matter (PM) formation.

Burning the hydrocarbons may be incomplete as unburned hydrocarbons(UHC) or volatile organic compounds (VOCs), and may exclude some lowreactivity compounds. Some of the hydrocarbon emissions are toxic.Hazardous air pollutants (HAPs) contribute to the ozone formation.Methane is a basic hydrocarbon and the impact of methane at the airportis highly dependent on local circumstances. Carbon monoxide is formedbecause of the incomplete combustion of carbon in the fuel, but alsocontributes to the ozone formation. The sulfur oxides are produced whensmall quantities of sulfur that are present in most petroleum fuelscombined with the oxygen from the air during combustion and contributedto the secondary particulate matter formation. Many of the non-volatileparticulate matter (PM) are the small particles of soot such as theblack carbon that forms as a result of incomplete combustion and fromthe aerosols of condensed gases. These components may be small enough tobe inhaled and can affect the elderly and young and have drasticconsequences under some environmental conditions, and for that reason,watched closely.

The nitrogen dioxide (NO₂) from the plume may be converted to nitricacid (HNO₃) vapor that interacts with ammonia in the atmosphere andforms ammonium nitrate (NH₄NO₃) particles. Oxidation reactions mayinvolve gaseous hydrocarbons from the plume and yield condensableorganic compounds that form organic aerosol particles. These componentsare health threatening in large concentrations and show the importanceof checking and maintaining proper emission levels. Other particulatematter (PM) such as the ground-level ozone, carbon monoxide, sulfuroxides, nitrogen oxides, and lead are common air pollutants that theaircraft may contribute. The climate may have some impact and in anyanalysis should be taken into consideration, such as for determiningmaintenance schedules. The climate impacts of aviation emissions in theplume and possibly at the exhaust may be considered.

Climate effects may have impact because of the interaction of solar andthermal radiation by gases such as carbon dioxide and water vapor andpollutants such as carbon monoxide, hydrocarbons and black carbonparticles arising from the incomplete combustion in the gas turbinecombustor. Any sulfur oxide emissions form sulfuric acid in the presenceof water vapor can further interact with ammonia in the earth's boundarylayer to form ammonium sulfate particles. The oxides of nitrogen areknown to impact the formation of ozone and form nitric acid at cruisealtitudes and ammonium nitrate particles in the boundary layer in thepresence of ammonia and will affect air quality and thus are monitored.The soot and black carbon particles at cruise altitudes interact withother chemicals such as sulfuric acid or nitric acid and form smallparticles that act as nucleating sites for condensation of water vaporpresent in the upper atmosphere under certain conditions. They can formlarger particles and condensation trails. Smaller particles may remainsuspended in the atmosphere longer and pose a risk to human health.

Other compounds may be associated with the aircraft exhaust and sensedby various sensors. These compounds include benzene, PAH, aldehydes,acetone, acetylene, chromium, xylenes, mercury, nickel, toluene,phenols, cresol and related compounds. The oxides of nitrogen are foundto occur primarily at approach, take-off and climb, known as the LTOcycle. The importance of measuring these compounds and other emissionsis apparent to those in the medical field. Ozone may impair the lungfunction, while carbon monoxide has cardiovascular effects. Nitrogenoxides will irritate the lung and lower the resistance to respiratoryinfections. Particulate matter may have impact on premature mortalityand aggravate respiratory and cardiovascular disease and change lungfunction and increase respiratory symptoms because of changes to lungtissues and structure and the altered respiratory defense mechanisms.The volatile organic compounds (VOCs) may irritate the eyes and therespiratory tract and cause headaches, dizziness, visual disorders andmemory impairment.

There are also environmental effects of air pollutants including ozone,carbon monoxide, nitrogen oxides, particle matter, and volatile organiccompounds. Processing at the aircraft or at an engine service providermay take into consideration the engine data and environmental emissionsdata. When sampling at or close to exit at the plane within about 1meter, emitted particles are log-normally distributed within a singlesize mode. This can be compared to about 200 meters downstream where thedownstream particle distributions exhibit two distinct modes. One maycorrespond to non-volatile and peak at roughly the same diametersobserved in the 1 meter samples. The other particles occupied by freshlynucleated sulfur and organic particles may peak at less than 12nanometers.

It has been found that for advected plume data on any given day, theengine-engine variability within a given class is less than 5% from massand number-based emission indices. Changes in ambient atmosphericconditions are likely to impact particulate matter emissions and alarger impact is expected on particle number than on particle mass.Thus, in an analysis, the weather conditions may be taken intoconsideration, for example, the barometric pressure, air moisturecontent, wind speed and air temperature.

It has been found that performance deterioration in the jet engine tendsto increase combustor inlet temperature, reflecting an increase in theexhaust gas temperature (EGT) and the fuel-air ratio, which increasesthe smoke emissions. Thus, a direct correlation may be made between theemissions at different phases of flight and a need for maintenance orengine overhaul. The wireless engine sensors may take into considerationdifferent parameters that may be measured, including the total andnon-volatile aerosols. The DGEOM is a number based geometric meandiameter that may be considered as well as the sigma as the geometricstandard deviation. The DGEOM M as the mass (volumetric metric) basedgeometric mean diameter may be taken into consideration, including thenumber based emission index (EIN) and the mass based emission index(EIM). Many jet engines demonstrate an increase in the DGEOM with power.It has also been found that with respect to chromium in the emissionmeasurements, it may not be significantly different to ambientconcentrations. It has been determined that the variability of the metaldistributions is much greater between engines than between engine loads.The mass of the ions collected on a filter can be low such that onlysulfate ions are above detection limits of a detection instrument.

Many of the thresholds that can be used by the engine service providerin determining a maintenance schedule can be those thresholds that arederived from the ICAO standards, which generally use 3,000 feet as abreak point and define the mixing height as a vertical region of theatmosphere where pollutant mixing occurs. Above that height, pollutantsthat are released generally do not mix with ground-level emissions anddo not have an effect on ground-level concentrations in the local area.Often the 3,000 feet level is used as a standard. Thus, the height ofthe mixing zone influences mainly the time-in-mode for approaching andclimb out and this is significant primarily when calculating oxide ofnitrogen emissions rather than hydrocarbon or carbon monoxide. Some ofthe thresholds may be seen as in the ICAO emission data and derivedemission factors released by the ICAO as set forth, for example, in FIG.12. This data and derived emission factors may be used to determinethresholds for alarm reports and determining a maintenance schedule inaccordance with a non-limiting example.

Even at 1,500 feet at conservative assumptions, the effects onground-level concentrations for carbon monoxide and hydrocarbons aresmall. The oxides of nitrogen may be significant, however, for airplaneelevations above 3,000 feet because of the ozone effect. Usually theoxides of nitrogen are nitrogen dioxide (NO₂), but nitrogen oxide (NO)is problematic and may be measured. In some instances such as inenvironmentally challenged basins, for example, the Los Angeles basin,the nitrogen dioxide concentration may be less than that of nitrogendioxide.

The changes in the oxide of nitrogen emission levels may also becorrelated with the related emissions to combustor flow parameters. Forexample, the sensitivity of specific fuel consumption (SFC) andcombustor flow parameters to component aging may be enhanced byincreases in cycle temperatures and pressures. This would result in ahigher sensitivity of the oxide of nitrogen emissions to enginedegradation for cycles. The engine performance deterioration may beassociated with different aging conditions over time and may include thephysical distortion of engine parts due to corrosion, the ingestion offoreign objects, the build-up of deposits (filing), erosion of parts andgeneral wear. The degradation is more manifest with physical changes inthe measurable engine parameters, including the exhaust gas temperature(EGT), fuel consumption at specific fuel consumption SFC, or the fuelflow (FF), the turbine inlet temperature, the low or high pressure spoolspeeds (N1 or N2 respectively), and/or engine pressure ratio (EPR) andchanges in other engine performance standards. It has been found thatcomponent efficiency losses in flow capacity changes may result inhotter cycle temperatures when a rise in the EGT occurs. For example, athreshold with EGT may be indicated and an overhaul required by a risein EGT between 30-50 K and/or an increase in SFC of between 2-4%. Thus,a 3% increase in the SFC would be a reasonable degradation limit, andthus, have an impact on the oxide of nitrogen emissions.

Different emissions correlations and equations used with cycles mayapply. An example is found in Table 6 for different engine cycles asdescribed in the article by Lukachko and Waitz entitled, “Effects ofEngine Aging on Aircraft NO_(X) Emissions,” ASME, 1997, the disclosurewhich is hereby incorporated by reference in its entirety. These typesof equations may be used in the analysis for example and are reproducedbelow:

Engine NO_(x) Correlation as EINO₂(NO_(x)) CF6- 50C2${{1.35 \cdot 0.0986 \cdot \left( \frac{P_{3}}{1\mspace{14mu}{atm}} \right)^{0.4}}{\exp\begin{pmatrix}{\frac{T_{3}}{194.4K} -} \\\frac{H_{0}}{\begin{matrix}{53.2\mspace{14mu} g\mspace{11mu} H_{2}O\text{/}{kg}} \\{{dry}\mspace{14mu}{air}}\end{matrix}{\;\mspace{14mu}}}\end{pmatrix}}} + 1.7$ GE90- 85B${0.0986 \cdot \left( \frac{P_{3}}{1\mspace{14mu}{atm}} \right)^{0.4}}{\exp\begin{pmatrix}{\frac{T_{3}}{194.4K} -} \\\frac{H_{0}}{53.2\mspace{14mu} g\mspace{11mu} H_{2}O\text{/}{kg}{\mspace{11mu}\;}{dry}{\mspace{11mu}\;}{air}}\end{pmatrix}}$ ASE${0.0041941 \cdot T_{4} \cdot \left( \frac{P_{3}}{439\mspace{14mu}{psia}} \right)^{0.37}}{\exp\left( \frac{T_{3} - {1471\mspace{14mu} R}}{345\mspace{14mu} R} \right)}$EHSCT$\mspace{31mu}{t_{res} \cdot {\exp\left( {{- 72.28} + {2.8\mspace{14mu} T_{adiabatic}^{0.5}\mspace{11mu}\frac{T_{adiabatic}}{38.02}}} \right)}}$

FIG. 13 is a graph for NO_(X) standards for higher thrust enginesshowing the grams per kiloNewton (g/kN) of thrust versus the pressureratio (PR). The graph applies for the NO_(X) standards for newlycertified gas turbine engines with rated thrust between 26.7 but lessthan or equal to 89.0 Kn and are differentiated by the pressure ratioand rated thrust. This type of graph is helpful to establish thethresholds for generating an alarm report and for aiding in maintenanceactions and determining a maintenance schedule. An example of relateddata is found in the Federal Register, Volume 77, No. 117, Monday, Jun.18, 2012 Rules and Regulations, page 36356, the disclosure which ishereby incorporated by reference in its entirety.

A plume analysis may be taken into consideration. It should beunderstood that the plume is a column of one fluid moving throughanother column and can be measured at the aircraft. Different techniquesmay be used to analyze the plume. A laser beam may be generated andoptics focus the laser beam into the exhaust plume and create a spark.Other sensing apparatus may be carried on an aircraft.

In a non-limiting example, the engine service provider (ESP) may receivethe engine data, including the engine emissions data and process thedata and perform an analysis to determine a maintenance schedule for theaircraft engine. This may include performing an analysis of the enginedata using a Bayesian network comprising a decision tree havingvariables comprising ranges of engine performance parameters. Otherpredictive analytics may be used. Data can be assembled as a stream ofdata packets containing compressed XML documents with a binary header tomaintain better tracking of data and the data can be broken into flightplan related, oceanic or host track reports. It is possible to use SPSSas a statistical package, for example, the Social Sciences RelatedSoftware and particular data analytics.

Data can be shredded using an XML shredder. A mutable data structure maybe used to create data strings. Range-partition tables may be used. TheBayesian network may be used as a graphical model that represents therandom variables and conditional dependencies via a directed acyclicgraph where the Bayesian network represents probabilistic relationshipsbetween the maintenance symptoms, including the engine data reflectiveof engine wear and problems relative to engine emissions to computeprobabilities for engine maintenance. Efficient algorithms can be usedto perform the inference and learning in the network.

FIG. 14 is a high-level flowchart 760 illustrating how the WEMS Modulemay generate an alarm report when the environmental engine emissionsexceed a threshold. Reference numerals begin in the 700 series. Theprocess starts (Block 702). Engine data is collected in real-time withinthe WEMS module (Block 704). This engine data includes engine emissionsdata from sensors such as the wireless engine sensors that sense theengine emissions, for example, particulate matter, hydrocarbons andoxides of nitrogen as non-limiting examples. This data may also includeemissions data from a plume analysis as described before.

At the WEMS module 20, the engine data is processed and parsed into datafor individual emissions components such as the concentration of oxidesof nitrogen or the concentration of selected hydrocarbons (Block 706).The data may also be parsed with regard to the phases of flight. Otheremission components are also sensed as described above and the listedare only non-limiting examples. The processor at the WEMS modulecompares each individual emissions component with the threshold for thatcomponent (Block 708) and a determination made if it exceeds or not(Block 710). If any emissions component exceeds the threshold, the WEMSmodule generates an alarm report to the flight deck (Block 712). If thethreshold is exceeded at the flight deck, a pilot can take correctiveaction or schedule maintenance (Block 714). The process ends (Block716). If an emissions component does not exceed the threshold, theprocess starts again.

In an operating example, the aircraft may approach the geographical areanear an airport. The local jurisdiction may have rigid environmentalrules mandating that engine emissions from an aircraft be within aspecific limit or threshold as imposed by the jurisdiction. For example,the total hydrocarbons or a specific hydrocarbon or a nitrogen oxide maybe required to be below a certain threshold, such as established by theICAO and described above. The local jurisdiction may also impose fineson any aircraft that may not be maintaining those emissions at or belowthe threshold and make spot checks of aircraft records such as from aWEMS module or other recordkeeping databases to determine if emissionsare greater than any thresholds. Measurements could even occur at theairport using sensing equipment to measure the exhaust. Also, emissionsmay be high at idle because the pilot is increasing thrust or turbinespeeds, causing excess emissions at the airport and exceeding thethreshold. The pilot may be able to make corrective actions bythrottling down or changing fuel flow. If not, then maintenance can bescheduled.

FIG. 15 is a high-level flowchart at 750 illustrating an example methodfor determining a maintenance schedule of an aircraft engine using theengine data, including the engine emissions data, and using for example,a Bayesian network. The process starts (Block 752) and full flightengine data, including the engine emissions, are collected (Block 754).This data will include the flight conditions and known weather patternsthrough which the aircraft flies since it may affect thrust, turbinespeeds and the environmental engine emissions at different phases offlight. After the aircraft lands, the full flight engine data isdownloaded to an engine service provider (ESP) (Block 756). However,data could be downloaded during flight as noted above. The ESP includesa large database of engine performance parameters determined from pastflights for the same engine and a database of engine data and engineperformance parameters determined from other aircraft engines of thesame type. The server located at the engine service provider processesthe full flight engine data, including the environmental engineemissions and data related to the flight conditions and weather, todetermine current environmental operating performance parameters byphase of flight most notably as related to engine emissions (Block 758).These environmental operating performance parameters include the averageor mean emissions for each component or pollutant, for example, asselected hydrocarbons or oxides of nitrogen at a particular phase offlight. There would be spikes and peaks of an engine emission that maydeviate from normal for very short periods depending on flightconditions that include weather or other deviations from normal. Theseare to be expected.

The server will then process the data and predict normal environmentaloperating performance parameters by phase of flight based on thehistorical database of flight conditions and known environmentalemissions for a number of past flights (Block 760). A Bayesian networkmay be used as an aid to predict normal environmental operatingperformance parameters using emissions data and the known flightconditions and weather impacts as obtained from the full flight enginedata that had been downloaded during the one flight.

The current environmental operating performance parameters arecorrelated with the predicted normal environmental operating performanceparameters based on an analysis of the wear and/or failures in theaircraft engine and an analysis performed to determine possible faultsand/or wear if components and a maintenance schedule determined (Block762). Different analysis algorithms may be used, including probabilityanalysis programs, learning algorithms and other statistical methods.These may also include correlation methods, multi-variable statisticalprocess analysis, pattern recognition methods, neural networks, fuzzylogic, hidden Markov models, discriminant analysis and others. Onepreferred example is a Bayesian network, for example, and includes adecision tree having variables comprising ranges of the engine operatingperformance parameters such as ranges of environmental emissions percomponent that is measured, such as a selected hydrocarbon. The processends (Block 764). As well known, a Bayesian network may representprobabilistic relationships between a failed component and theenvironmental emissions. Given the environmental emissions, theprobabilities of failed components may be determined. The Bayesiannetwork is only one type of analysis that may be used as noted above.

FIG. 16 is a high-level flowchart showing a process for using currentweather forecasting data and the WEMS module and its engine data tochange engine operating parameters during flight based on predictedflight operations caused by weather changes. The process starts (Block770) and data is collected in the WEMS module regarding sensed engineparameters, including environmental engine emissions (Block 772). Theengine data is downloaded to the engine controller (Block 774) such aslocated at the flight deck. Weather forecasting data is received withinthe engine controller (Block 776). Engine operating parameters aredetermined based on the engine data and current weather forecasting data(Block 778) and the engine operating parameters changed (Block 780) asthe aircraft travels into the changed weather patterns. The process ends(Block 782). Big data analytics may be used on the weather forecastingdata coupled with the WEMS data for predicted flight information andchanging the engine operating parameters during flight. Various sensorsmay determine how much carbon emission is released into the atmosphereand fuse the weather forecasting data using plume diagnostics todetermine the geographic impact on emissions. Weather forecasting datamay be obtained from a weather service provider. The weather serviceprovider's extensive data analytics may be used, including the data forwinds aloft, temperature, pressures, and similar data points. It ispossible to make changes not only to the engine operation, but also toother avionic systems, including auto pilot systems such as for reducingdrag-coefficients at optimum altitude. The extensive weather data canalso be coupled with past engine data analytics obtained from the WEMSmodule with regard to how the engine in the airframe operates when theplane flies over different terrain, such as desert, ocean, tundra andother geographical areas. This information may be used to determinecarbon credits, which refers to the tradable certificates or permitsrepresenting the right to emit 1 ton of carbon dioxide or the mass ofanother greenhouse gas with a carbon dioxide equivalent to 1 ton ofcarbon dioxide. It is possible to detect a severe weather front using asevere weather detection and warning method such as disclosed incommonly assigned U.S. patent application Ser. No. 15/003,935. Theengine controller may include a transceiver that can work with thesevere weather detection and warning devices to receive signalstherefrom. As new geosynchronous earth-observing satellites areintroduced, many have the capability to collect atmospheric soundingssuch as temperature and moisture content. The system has hemisphericalcoverage and high resolution such as 4 km and a rapid refresh of about 5to 10 minutes and can be used to produce stability (AS) and windmeasurements which are combined with ground-based radar to produce agraphical representation of future weather to make the flight cabin moreaware of weather patterns. It is possible to measure the Exhaust GasTemperature and correlate that with sensed carbon emissions anddetermine carbon credit data and in some cases correlate that withweather patterns. Also, it is possible to monitor real time and fullflight engine data obtained from the WEMS module and measure carbonemissions to determine carbon credits and add into the analysis weatherparameters described above.

Referring now to FIGS. 17 and 18, there is illustrated in greater detailan aircraft monitoring system 800 as part of a WAIC as generallydescribed before. For reference, numerals begin in the 800 series. Theaircraft 801 includes a plurality of aircraft compartments. Eachaircraft compartment includes a gateway network node 804 and having awireless gateway transceiver 806 and optionally a memory 807. Aplurality of wireless sensors 808 are each connected to an aircraftcomponent to be sensed. As better shown in FIG. 17, each wireless sensor808 includes a sensor transceiver 810 configured to receive aircraftdata from a sensed aircraft component and transmit that aircraft data tothe wireless sensor server 812 via the gateway network node 804positioned within the respective aircraft compartment 802. Each gatewaynetwork node 804 may be connected to an existing on-board communicationsnetwork 820 such as an avionics data bus and also each gateway networknode 804 may be configured in a multi-hop network configuration tocommunicate with each other and with the wireless sensor server 812 andwireless sensors 808 using a wireless communications protocol. Anexample of the wireless communications protocol includes at least one oftime division multiple access (TDMA), frequency division multiple access(FDMA), code division multiple access (CDMA), space division multipleaccess (SPMA), and orthogonal frequency division multiplexing (OFDM).

The aircraft may include many different aircraft compartments and FIG.18 illustrates the compartments as a flight deck 802 a, cabincompartment 802 b, avionics compartment 802 c, cargo compartment 802 d,bilge 802 e, engine nacelles 802 f, fuel tanks 802 g, vertical andhorizontal stabilizers 802 h, landing gear bays 802 i and flap members802 j. The different aircraft components to which the wireless sensors808 interface may include an actuator or display as non-limitingexamples. The wireless sensor server 812 includes a server transceiver812 a, processor 812 b and memory 812 c. The server processor 812 b isconfigured to store within the memory 812 c the aircraft data receivedfrom each of the gateway network nodes 804 in one non-limiting example.The on-board communications network 820 at the engine nacelle 802 f maycomprise a full authority digital engine controller/engine control unit(FADEC/ECU) as described previously and connected to the enginemonitoring module, which in this example operates as a gateway networknode 804 to communicate with other gateway network nodes.

The WEMS module 20 is a part of this wireless avionicsintra-communications (WAIC) radio communication network betweendifferent points on the one aircraft and operates for safety-relatedapplications. The WAIC network can meet standards such as provided inthe technical characteristics and operational objectives for wirelessavionics intra-communications (WAIC) as promulgated by the InternationalTelecommunication Union (ITU).

Different wireless sensors 802 in the different compartments 802 mayinclude sensors to sense cabin pressure, sense smoke in unoccupied andoccupied areas, sense fuel tanks and fuel lines and sense proximity andleaks at the passenger and cargo doors and panels. Sensors can beincluded for valves and other mechanical moving parts, ECS, EMIdetection, emergency lighting control, general lighting control, andcabin control. Some sensors can be placed on removable items in thecabin such as for inventory control. Over 130 smoke sensors may be usedin occupied areas. Larger planes can have about 80 fuel tank and fuelline sensors, which operate as a low data rate application of less than10 Kbit/S.

Other exterior or outside sensor applications may include ice detection,landing gear or proximity sensing such as tire pressure and braketemperatures. Landing gear sensors may include wheel speed sensors foranti-skid control and position feedback for steering. Other sensorapplications include flight control sensing and sensors associated withposition feedback and control parameters. Cargo compartment data andstructural sensors may be used. These sensors may operate at low datarates. High data rates such as greater than 10 Kbit/S first rate pernode may be used both inside and outside the aircraft structure. Highdata rate applications could include air data sensors, a FADEC aircraftinterface, engine prognostic sensors, the flight deck and cabin crewvoice sensors, fixed imagery sensing at the flight deck, cabin crewfixed imagery sensing, and flight deck crew motion video sensing. Otherapplications could include those applications associated with theavionics communications bus, the audio communication system, structuralsensors, external imaging sensors such as cameras and active vibrationcontrol. Each wireless sensor may included an antenna having a beamwidththat can vary between 50 to 180 degree beamwidths and some low gainantennas may have beamwidths greater than 180 degrees.

The WEMS module 20 is beneficial for power generation design such thataircraft turbine designers benefit from data collected during continuousfield operation of their engines. This allows for design improvements inthe safety, reliability and efficiency of future engine systems. Missioncritical networks (MCN) will also be able to explore relatedopportunities for the commercial aviation market based on data obtainedby the WEMS module interoperative with the EWSN 600, which is apotential driver for future electronic enabled airplane healthmanagement (AHM) that is real-time, continuous and proactive. Onebeneficial opportunity is applicable to commercial/military helicoptertechnology with health and usage monitoring systems (HUMS).

Different wireless engine sensors can be used in the engine wirelesssensor network 600. Typically, each wireless engine sensor forms awireless engine sensor node and provides a radio interface and processorcapability. The wireless engine sensors can operate at 600 or moredegrees Centigrade in the harsh environment of the jet turbine engine tomeasure strain, heat and gas. These wireless engine sensors areadvantageous over wired sensors that are difficult, impractical orexpensive and difficult to implement with rotating components thatdamage the wire leads, making wired sensors impractical in an aircraftengine. Some wireless engine sensors use a passive power source becausebattery power is not feasible.

These wireless engine sensors are typically lightweight and conformalfor use on different rotating and non-rotating surfaces and can operateinside the turbine jet engines without unbalancing the engine ordisrupting the aerodynamics. It is possible for the wireless enginesensors to measure strain with 50 KHz variations and operate at evenhigher frequencies with modal vibrations that occur two to about threetimes the vane passing frequency. In one example, the wireless enginesensors are formed from surface acoustic wave (SAW) devices that operatein excess of 1,000 Degrees C., thus allowing them to be used fordifferent wireless strain, temperature and sensing applications insevere radio frequency (RF) multipath and Doppler environments.

In one non-limiting example, SAW sensors capture the RF energy from aresonant antenna structure during interrogation such as a signalemanating from the transceiver of the WEMS module to excite thedifferent surface acoustic waves by piezoelectric coupling to asubstrate material. Typically the acoustic waves are delayed betweenmetallic reflectors in proportion to the strain experienced at thatinstant when strain is imparted, and thus, the strained sensing isintrinsic to the device. The reflected acoustic wave is re-radiated backinto the RF domain and the now-modulated data signal is received by theremote RF interrogation unit such as by the transceiver at the WEMSmodule and process engine data through any associated EWSN CPU. Anydifferential time delay between the two strain reflectors is computed,for example, at the EWSN CPU in this non-limiting example based on thephase of the received signal. Any time span between the RF “data” andthe “reference” signals is typically about 100-200 nanoseconds and thusa jet engine spinning at a high RPM is frozen in position when the datapoints are collected.

The advantages of the wireless engine sensors as described include thepassive power feature with no complex circuitry failing at hightemperatures together with the wireless technology that is small,lightweight and conformal to minimize the impact on engine performance.

Referring again to FIG. 10, it is also possible to have a passive,wireless engine sensor network 600 that uses a microwave acousticsensor, for example, using acoustic wave technology as a bulk acousticwave (BAW) device, film bulk acoustic resonator (FBAR), acoustic platemode (APL) device, or a surface acoustic wave (SAW) device as describedabove and as described in the incorporated by reference U.S. Pat. No.9,026,336, and commonly assigned U.S. application Ser. No. 14/810,535,and published as U.S. Patent Publication No. 2015/0330869, thedisclosure which is hereby incorporated by reference in its entirety.

The wireless engine sensors can also use microelectromechanical systems(MEMS) technology and RF powered LC sensors and high temperaturethermo-couples or even optical sensors as described in theabove-identified and incorporated by reference patent applications andpatents.

The wireless engine sensor could be formed as an inductor with alead-lanthanum-zirconate-titanate (PLZT) ceramic capacitor havingtemperature dependent characteristics and include an inductor-capacitor(L-C) tuned electronic oscillator that incorporates the temperaturesensitive materials with a change in the value of the capacitance due tothe temperature variation translated into modulation in the oscillatorfrequency as described in the above-identified and incorporated byreference patents and patent applications.

A communications module could implement communications using a BFSK(binary phase shift key) modulation and frequency hopping spreadspectrum (FHSS) multiple access with a digital data interface, frequencysynthesizer, and transmitter and receiver. Microprocessor andprogrammable logic can be included as a communications protocol stackimplementation. Each wireless engine sensor as a node could transmit itsown power capability data in order to receive power data from one ormore other sensor nodes and can determine an optimum data transmissionroute through a wireless sensor communication network. Typically a datatransmission route would be through the wireless sensor node or nodesthat have the greatest power capability. Some power routing can beimplemented with one of at least ad-hoc, on-demand distance vectorrouting protocol (AODD), dynamic source routing (DSR) and global staterouting (GSR).

Each wireless engine sensor node could also transmit data representativeof its position and if in a fixed position that position data will be aconstant. If the wireless engine sensor is located on a rotatingcomponent, then the sensor position would change, and the position datawould be preferably transmitted simultaneously with the sensor data andpower capability data. It is possible to use any received identificationdata to determine if a wireless engine sensor node transmitsidentification data as a member of the network. Each wireless enginesensor node could be assigned a given access time to the network similarto a TDMA system. It is possible to use a vibration-powered generator aspart of the power supply that is driven by engine vibration and convertsmechanical power to electrical power. Different power scavengingmechanisms can be implemented using MEMS technology to make the nodes assmall as possible.

As noted before, the WEMS module 10 includes an EWSN CPU as shown inFIG. 10 that could be remotely configurable by a processor in the WEMSmodule, on the crew or a processor at the flight deck, or by the EngineService Provider operations center 562. The operations center can alsotransmit instructions to the EWSN 600 via the WEMS module to varysampling rates on specific wireless engine sensors. The sampling ratesare programmable for each of the different wireless engine sensors topermit programmable sensor monitoring, provide detection and diagnosisof faults and allow intelligent maintenance for “real-time” monitoringof critical engine parameters using “customized sampling.”

Use of EWSN in conjunction with the WEMS module provides for improvedmonitoring of reduced thrust take-offs to the minimum required for safetake-off because different wireless engine sensors can be sampled at agreater rate, for example, at take-off and thrust could be adjusted. Onsome occasions when the full thrust would be more than safely requiredsuch as for lower weight flights, long runway or head wind, it ispossible to choose a thrust setting below the full thrust by telling theengines via the FMC (Flight Management System) that the OAT (Outside AirTemperature) is much higher. Temperature control using the EWSN isbeneficial and various take-off tables can be used as assistance.

As noted before, it is possible to use the exhaust gas temperature (EGT)margin as the buffer between the engine's normal operating EGTtemperature and its maximum EGT, i.e., the temperature at which it mustbe inspected, overhauled or replaced. The higher EGT may be anindication of the HPC wear that can cause compressor stall. Differentvariables can be measured such as flow through a fuel metering valve, avariable bleed valve, variable stator vein, the fan speed (N₁), the corespeed (N₂), fan inlet temperature, fan inlet pressure, the LPC outlettemperature, the combustor static pressure, the HPT exhaust gastemperature and the core exhaust pressure. Other actuators can bemeasured including the fuel flow (WF), variable bleed valve (VBV) andvariable stator veins (VSV) operation.

The EGT can be compared with the primary engine power indication calledthe engine pressure ratio (EPR). For example, at full power EPR there isa maximum permitted EGT limit. Once an engine reaches a stage where itreaches this EGT limit, the engine requires maintenance. The amountbelow the EGT limit is the EGT margin and this margin would be greatestwhen the engine is new or has been overhauled. The EGT margin is abuffer between an engine's normal operating EGT temperature and itsmaximum EGT and the higher EGT is an indication of the HPC wear that cancause a compressor stall. Engines are rarely used at the full thrustrating and usually have a level of derate for take-off power thatreduces the EGT and increases the EGT margin. Derates at 5% and 10% willreduce EGT and increase the EGT margin by as much as 36 degrees.Derating can be used if the aircraft take-off weight is less thanpermitted maximum take-off weight (MTOW) and a long runway is availableor the OATS are relatively low.

Air frame health management allows in-flight diagnosis and assessmentthrough the integration of the wireless engine sensors, sensoringmaterials and advanced algorithms that reconstruct damage fields andestimate structural durability and remaining useful life. Thesealgorithms could be incorporated within the WEMS module and incorporateadvanced information processing techniques including neural networks,expert systems, fuzzy logic systems, pattern recognition, signalprocessing for spectral analysis and feature extraction and statisticalalgorithms for detection, estimation, prediction and fusion. It is alsopossible to use the EWSN 600 and WEMS module 20 to maintain LRU (linereplaceable unit) fault states that have a gas path impact such asoffset errors in gas path sensors or actuators. This could reduce falsealarms and false ambiguities. The WEMS module 20 as described alsoenables greater control over life limited parts (LLP) such as therotating turbine engine parts that are critical to engine integrity andare difficult to inspect outside the engine. The WEMS module 20 inconjunction with the wireless sensor network 600 provides enginecondition base maintenance (CBM) to optimize engine maintenance costswhile increasing operational performance with advanced fleet managementand removal planning of aircraft engines.

The wireless engine sensors may sense engine parameters as engine databased on an engine sampling algorithm that is received from the WEMSmodule 20. The new algorithm may be uploaded via a ground basedtransceiver and processor as part of an engine data control center 300that processes engine data. The control center 300 will generate andtransmit back to the aircraft a new engine sensing algorithm, which maybe transmitted directly to the WEMS module 20 and then to the wirelesssensor network (EWSN) 600 or to the WEMS module via the CWLU 532 in mostcircumstances. The WEMS module 20 may store dynamic or staticalgorithms. Dynamic algorithms that are uploaded to the WEMS module mayinstruct the sensor network 600 to sample new engine data viainstructions to individual sensors to start, stop, or change a samplingrate. The ground based control center 300 generates engine performancereports indicative of the engine health and status. These can bemini-reports by phase of flight corresponding to taxiing, take-off,climb, cruise, descent, final approach, and taxiing.

The comparative fuel performance of turbine engines may be analyzedusing a differential fuel flow by phase of flight. This could include acomparative fuel performance of dual turbine engines or a plurality ofturbine engines mounted on the aircraft and using common environmentalfactors. For example, each phase of flight corresponds to a certain timeperiod or range of time such as taxiing, take-off and the other phasesas noted before. The weight of the fuel at each phase of flight orcombination of phases or the entire flight for each turbine engine canbe calculated as the absolute value at each phase using, for example,the weight of fuel consumed at one of the phases, or at a combination ofphases, or all the phases added together for engine 1 and the weight offuel consumed at one or more phases in engine 2 when there are twoengines. Different formulas may be used as known to those skilled in theart depending on the type of engine and aircraft.

Because the algorithms are uploaded to the WEMS module 20 and data istransmitted from the wireless engine sensors 600 to the WEMS module 20and into the wireless LAN unit 532 within the aircraft, the pilot mayhave access to the data for processing on board the aircraft. The pilotmay initiate engine operating changes, such as shutting down an engineduring an emergency or making pilot initiated changes to sensor samplingat a selected engine if the pilot wants additional data on a specificengine component. The pilot could initiate other engine operationchanges. It is preferred that data is off-loaded to the ground basedcontrol center 300 for processing. The WEMS may be configured on-the-flywith uploaded new engine sampling algorithms or other algorithms thatare used to operate the engine and other aircraft systems. An importantconsideration in engine operation is the Exhaust Gas Temperature (EGT),which can be indicative of the operating efficiency of the turbineengine. For example, if the engine is in need of maintenance or hasstructural integrity problems or other issues, often the exhaust gastemperature will increase over a period of time and be higher thannormal. The pilot could initiate additional engine sensor sampling togain a better understanding of engine operation and performance duringdifferent phases of flight and maintain better control over how theexhaust gas temperature changes during the phases of flight or otherflight circumstances. The system is advantageous to monitor the healthand status of turbine engines from “on the engine” rather than from theflight deck in certain circumstances.

It should be understood that the exhaust gas temperature is an excellentmeasure of engine health and an overall indicator of mechanical stresswhere the EGT rises over time as the engine uses up its useful on-winglife. Determinations can be made at the ground based control center 300regarding any temperature differences between the actual operatingtemperature and an absolute maximum operating temperature known asredline that becomes a function of the EGT margin. The ground basedcontrol center 300 can determine with the pilot when full thrust isapplied and determine if the EGT maximum is surpassed. Also, the groundbased control center 300 may determine how the pilots are operating theengine, which can have an impact on the exhaust gas temperature andcause engines to fail early. Pilots can later be educated for betterflight practices.

Many modifications and other embodiments of the invention will come tothe mind of one skilled in the art having the benefit of the teachingspresented in the foregoing descriptions and the associated drawings.Therefore, it is understood that the invention is not to be limited tothe specific embodiments disclosed, and that modifications andembodiments are intended to be included within the scope of the appendedclaims.

That which is claimed is:
 1. A monitoring system for an aircraft engine,comprising: a plurality of wireless engine sensors associated with theaircraft engine and configured to sense engine emissions duringdifferent phases of flight and generate environmental emissions enginedata that includes at least the concentration of carbon dioxide, carbonmonoxide, hydrocarbons, oxides of nitrogen, and particulate matteremitted as exhaust from the aircraft engine and transmit theenvironmental emissions engine data; a plume sensor carried by theaircraft and configured to measure particle emissions downstream fromthe aircraft engine in a hot exhaust plume during the phases of flightand generate exhaust plume data that includes at least the concentrationof carbon dioxide, carbon monoxide, hydrocarbons, oxides of nitrogen andparticulate matter contained within the exhaust plume and transmit theexhaust plume data; an engine monitoring module comprising: a housingconfigured to be mounted at the aircraft engine, a wireless transceivercarried by the housing and configured to receive the environmentalemissions engine data and exhaust plume data, a memory carried by thehousing, and a processor carried by the housing and coupled to thememory and the wireless transceiver and configured to: process and parsethe environmental emissions engine data and exhaust plume data intoemissions components for the concentrations of carbon dioxide, carbonmonoxide, hydrocarbons, oxides of nitrogen and particulate matter duringthe phases of flight, and compare each emissions component with athreshold for a phase of flight, and if any emissions component exceedsthe threshold for that phase of flight, the processor generates an alarmand said wireless transceiver transmits the alarm into the aircraft,wherein said processor is configured to store in the memory theemissions components to calculate carbon credits.
 2. The monitoringsystem according to claim 1, wherein the plurality of wireless enginesensors are mounted on the aircraft engine.
 3. The monitoring systemaccording to claim 1, wherein said plume sensor comprises a wirelessplume sensor configured to transmit wirelessly the exhaust plume data tothe wireless transceiver of the engine monitoring module.
 4. Themonitoring system according to claim 1, wherein said processor at saidengine monitoring module is configured to receive and process weatherdata during flight.
 5. The monitoring system according to claim 1,comprising at least one communications device positioned within a flightdeck of the aircraft that receives the alarm.
 6. The monitoring systemaccording to claim 1, wherein the environmental emissions engine datafurther comprises the concentration of total hydrocarbons (THC), totalorganic gases (TOC), and sulfur dioxide.
 7. The monitoring systemaccording to claim 1, wherein the phases of flight include at least oneof the aircraft's taxiing, take-off, climb, cruise, descent, finalapproach and taxiing.
 8. The monitoring system according to claim 1,wherein the environmental emissions engine data comprises data regardingthe sensed exhaust gas temperature (EGT) of the aircraft engine duringflight.
 9. A monitoring system for an aircraft engine, comprising: aplurality of wireless engine sensors associated with the aircraft engineand configured to sense engine emissions and the exhaust gas temperature(EGT) during different phases of flight and generate environmentalemissions engine data that includes the EGT and at least theconcentration of carbon dioxide, carbon monoxide, hydrocarbons, oxidesof nitrogen, and particulate matter emitted as exhaust from the aircraftengine, and wirelessly transmit the environmental emissions engine data;an engine monitoring module comprising: a housing mounted at theaircraft engine, a wireless transceiver carried by the housing andconfigured to receive environmental emissions engine data, a memorycarried by the housing, and a processor carried by the housing andcoupled to the memory and the wireless transceiver and configured to:process and parse the environmental emissions engine data into emissionscomponents for the concentrations of carbon dioxide, carbon monoxide,hydrocarbons, oxides of nitrogen and particulate matter during thephases of flight, and compare each emissions component with a thresholdfor a phase of flight, and if any emissions component exceeds thethreshold for that phase of flight, the processor generates an alarm andsaid wireless transceiver transmits the alarm into the aircraft, whereinsaid processor is configured to store in the memory the emissionscomponents to calculate carbon credits.
 10. The monitoring systemaccording to claim 9, wherein said processor at said engine monitoringmodule is configured to receive and process weather data during flight.11. The monitoring system according to claim 9, comprising at least onecommunications device positioned within a flight deck of the aircraftthat receives the alarm.
 12. The monitoring system according to claim 9,wherein the environmental emissions engine data further comprises theconcentration of total hydrocarbons (THC), total organic gases (TOC),and sulfur dioxide.
 13. The monitoring system according to claim 9,wherein the phases of flight include at least one of the aircraft'staxiing, take-off, climb, cruise, descent, final approach and taxiing.